The calculated distance (air line) between Ciutat Vella and Sant Boi de Llobregat is approximately 8 miles respectively 12 kilometers.
By car or train, the actual journey to Sant Boi de Llobregat is certainly longer, as only the direct route (as the crow flies) between Ciutat Vella and Sant Boi de Llobregat has been calculated here.
Air line (approximately)
12 kilometers
7 nautical miles